The Cost Of Spam

[I]n a new paper in the Journal of Economic Perspectives, Justin Rao of Microsoft and David Reiley of Google (who met working at Yahoo) have teamed up to estimate the cost of spam to society relative to its worldwide revenues. The societal price tag comes to $20 billion. The revenue? A mere $200 million. As they note, that means that the "'externality ratio' of external costs to internal benefits for spam is around 100:1. Spammers are dumping a lot on society and reaping fairly little in return." In case it's not clear, this is a suboptimal situation.